The present invention relates to a novel and useful apparatus and method for non-invasively analyzing liquid medium components in a bag.
Liquid compounds are often placed in bags for various purposes. For example, the use of total parenteral nutrients (TPN), which are eventually the source of intravenous feeding, are stored in transparent or translucent flexible bags. TPN compounds are commonly mixed in pharmacies using commercially available compounders which accept three or more TPN compounds and automatically mix these compounds into an appropriate container such as an intravenous (I.V.) bag. Intravenous use of the bags usually takes place at a later time in a hospital or medical facility. Typical compounds include 70% dextrose injection U.S.P., 10% Travasol (amino acid) injection, Intralipid 20% fat I.V. emulsion, sterile water, and many others.
Presently, methods such as color coding are relied upon to avoid making errors during the compounding or mixing process. Namely, different tubes feeding the I.V. bag possess connectors of different colors which correspond to the colors of the specific mixing positions on the compounder. For example, setting a red indicator on a compounder for 100 milliliters would deliver 100 milliliters from a starting bottle connected to the tubing line which possesses red connectors. However, there is no assurance that the correct compound was initially connected to the red tubing line. Consequently, an incorrect connection of the tubing between bottles of dextrose solution and water, for example, may have dire consequences, such as death for patients with sugar intolerance.
Many of the TPN compounds are clear liquids. That is to say, water, amino acid injection, dextrose injection, and electrolytes are clear liquids precluding visual distinction among them. Furthermore, it is preferable to perform identification of TPN components non-invasively and rapidly to minimize potential contamination and to minimize analysis time by personnel.
An article entitled "Near Infrared Multi-Component Analysis of Parenteral Products Using the InfraAlyzer 400," by Rose et al. examined meglumine and meglumine diatrizoate in 30% diatrizoate meglumine injections solutions using diffuse reflectance in the near infrared region. The best combinations of three or four wavelength filters from nineteen (19) available wavelength filters were selected using multiple regression statistical methods. The specific wavelengths were not identified.
An article entitled "The Spectrophotometric Absorbance Of Absorbance of Intralipid" by Carne et al. develops calibrations for Intralipid in water in concentrations from 2.5 to 40 mg/ml at six (6) visible wavelengths between 505 and 626.6 nanometers. Intralipid interferes with spectrophotometric analysis of oxyhemoglobin, carboxyhemoglobin, and total hemoglobin.
A writing entitled, Simple Methods For Quantitative Determination of Procaine Hydrochloride In Parenteral Products by Das Gupta et al. presents calibrations in the ultraviolet region of spectrophotometry. Specifically, the Das Gupta reference obtained calibrations at 228 nanometers for buffered solutions of procaine hydrochloride in the 0-20 microgram/ml concentration range.
An article entitled "Nondestructive NIR and NIT Determination Of Protein, Fat, And Water In Plastic-Wrapped, Homogenized Meat" by Isaksson et al., describes NIR measurements of proteins by diffuse reflectance in meat samples with and without plastic coatings. Samples were placed in a rubber cup prior to covering the meat sample with plastic laminant.
U.S. Pat. Nos. 4,800,279 and 5,002,397 describe methods and devices for visible and near-infrared evaluation of physical properties of samples.
U.S. Pat. No. 4,872,868 shows an analyzer for collection bags which provides an envelope that permits the insertion of reagent's test strips and the like.
U.S. Pat. Nos. 3,857,485 and 3,924,128 teach a method of analyzing sample containers by liquid scintillation spectrometry which utilizes light transmission sealing means to prevent entry of ambient light or the escape of light from the photomultiplier tube detection devices.
U.S. Pat. No. 5,239,860 describes a sensor for continuously measuring alcohol and gasoline fuel mixtures in a clear Teflon tube using a pre-determined optical path and electromagnetic radiation at a pair of wavelengths which are generated by rapidly switching currents through a light-source. Thermopile detectors are used to detect an increase in temperature due to light transmitted through the flowing gasoline/alcohol mixture.
An apparatus and method for identifying solutions in a translucent transparent or semi-transparent plastic bag, such as parenteral nutrients, non-invasively, qualitatively and quantitatively would be a notable advance in the chemical analysis field.